This invention relates to improved apparatus and methods for weighing rolling stock, particularly railroad cars, in motion. More particularly, it relates to improved apparatus and methods for weighing in motion rolling stock, by weighing each axle as it enters a weigh bridge. More particularly still, it relates to improved apparatus and methods which can be retrofitted and used in conjunction with most existing weigh bridges regardless of the length of the weigh bridge, to weigh in motion rolling stock, by weighing each axle as it enters the weigh bridge.